How are the 24 solar terms in China formed?

Solar terms refer to the twenty-four solar terms and climate, which is a supplementary calendar formulated by China in ancient times to guide farming, and is the crystallization of the long-term experience and wisdom of the working people of the Han nationality.

Since China was an agricultural society in ancient times, agriculture needed to have a strict understanding of the operation of the sun, and farming was carried out entirely according to the sun. Therefore, the "twenty-four solar terms" that reflect the solar cycle alone are added to the calendar as the standard for determining leap months.

Historical origin

In ancient China, the sundial was measured by earth gauge, and the longest sundial was defined as "solstice" (also called the day from full day to day, long day to day, and winter solstice), and the shortest sundial was "short day to day" (also called short day to day and summer solstice). One day in spring and autumn is the same length of day and night, which is designated as "vernal equinox" and "autumnal equinox". There were only four solar terms in Shang dynasty, but it developed to eight in Zhou dynasty and was completely established in Qin and Han dynasties. In BC 104, the taichu calendar written by Deng Ping officially set 24 solar terms in the calendar, and defined the astronomical position of the 24 solar terms.

The name of the twenty-four solar terms first appeared in Huainanzi? Astronomical training, historical records? The concept of yin and yang, four seasons, eight places, twelve degrees and twenty-four solar terms is also mentioned in Taishi Gongxu. During the period of Emperor Wu of the Han Dynasty, Luo compiled solar terms into the calendar, stipulating that the month without neutral gas was the last month of leap month.

Each of the 24 solar terms corresponds to a certain position reached by the sun every time it moves 15 on the ecliptic. The twenty-four solar terms are divided into 12 solar terms and 12 solar terms, which correspond to each other one by one. The twenty-four solar terms reflect the annual apparent motion of the sun, so their dates are relatively fixed in the Gregorian calendar. The solar terms in the first half of the year are on the 6th, the solar terms in the second half of the year are on the 8th and the solar terms are on the 23rd. The difference between them is 1? Second.

China's orthodox 24 solar terms are based on Henan. China's lunar calendar is a combination of yin and yang, which is based on the movement of the sun and the moon, so adding 24 solar terms can better reflect the cycle of the sun's movement.

The 24 solar terms are: beginning of spring, rain, fright, vernal equinox, Qingming, Grain Rain, Changxia, Xiaoman, Mangzhong, Summer Solstice, Slight Summer, beginning of autumn, Early Summer, Millennium, Autumn Equinox, Cold Dew, Early Frost, beginning of winter, Light Snow, Heavy Snow, Winter Solstice, Slight Cold and Great Cold.

2016165438+1October 30th, China's "Twenty-four solar terms" was officially listed in UNESCO's representative list of human intangible cultural heritage.